Packaging containers for food products, e.g. packaging containers with liquid foods, such as, for example, juice, milk etc., or foods of a more solid nature such as, for example, soups, vegetables etc., are often manufactured from a packaging laminate which is cut to, folded and thermosealed to a finished packaging container, for example of parallelepipedic configuration. The packaging laminate comprises a carrier layer of fibrous material, such as paper or paperboard which is coated on either side with layers of thermoplastic material, such as, for example, polyethylene. The packaging laminate often also comprises a barrier layer of metal such as, for example, aluminium.
A plurality of different packaging machines for the production of these or similar types of packaging containers is known in the art. A number of these operate with tubular packaging container blanks which are fed into the machine in the flat-laid state and are raised therein so that they obtain a preferably square or rectangular cross section. During their displacement through the packaging machine, the packaging containers are progressively provided with a liquid-tight bottom, which is normally formed by compressing and sealing a first end of the packaging container blank. The packaging container is thereafter moved further to a filling station in which the desired type of contents is fed into the packaging container, whereafter the still as yet open end of the container is sealed by, for example, compressing and sealing.
Each individual packaging container which is moved through a packaging machine of this type is preferably supported by some form of conveyor which ensures that the packaging containers are moved between different stations for, for example, bottom forming, filling and top forming. In packaging machines which operate at high speeds and with rapid accelerations, it is of crucial importance that the individual packaging containers are both placed and retained in the correct position for the different operational phases, for example bottom forming and filling and, as a result, it is now usual that each individual packaging container is supported by a carrier or cassette which abuts on three sides against the packaging container and fixes it in a carefully predetermined position in relation to the conveyor and the different stations. In addition to the accurate positioning of each individual packaging container in the longitudinal and transverse directions of the conveyor, it is, in particular in mechanical processing, for example bottom or top sealing of the packaging container, also of major importance that the vertical position of the packaging container is accurately defined when it is located in the conveyor. A cassette possessing these properties is described, for example, in EP 1062160. This cassette displays an open design which makes it possible to move the packaging container into or out of the cassette at both ends thereof and it can position the packaging container in the vertical position in that one or more of the flexible, projecting parts or corner flaps of the packaging container are utilised for fixing the packaging container in the correct position. The positioning of the packaging container in the vertical direction in the cassette normally takes place using an apparatus for pushing the packaging container, the apparatus comprising a carrier plate which pushes the packaging container in, for example, an upward direction in the cassette.